Any idea on bandwidth used daily per tb ? This looks like a fantastic alternative to the energy waste of pow mining.

Assuming you mean disk bandwith, it reads one 4096th of the data of the drive each block, with a block target of 4 minutes, so 1/4096 of 1TB 360 times per day is about 88GB read per day per TB of storage.

Very interesting concept. Is pool mining theoretically possible or would the network consist of all solo miners?

Since plots are good only for mining to one address, the only way a pool would work under the current protocol would be for a pool to supply addresses to miners, and have them generate plots and mine to those addresses. The pool would be able to gauge approximate disk usage based on how low the average result is. The problem with that though, is miners would have to regenerate plots in order to switch pools, which is a slow process, so miners would be fairly stuck on the pools they chose.

One possibility for the future might be to allow an address to declare that their mined coins go to an alternate address. The user could submit their results every block to the pool so it can estimate disk usage, and dish out coins accordingly.

You mention that the miner will be released 3 hours before launch. Will that be enough time to prepare a 1TB hard drive?

No. If you have a good processor, you can probably do about 100GB in 3 hours. You can run 2 instances of the miner, one for generating plots, and one for mining with plots at the same time, and it will mine with what you've prepared.

Yes. When mining, run an instance of the miner on each drive. You may want to cap the ram usage though(ex: -Xmx500m), since the JVM tends to store no longer needed stuff too long and uses up all your ram if you don't force a lower cap. The .bat/.sh scripts included in the miner will already have that flag set.